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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/ia64/lib/checksum.c | |
download | linux-next-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/ia64/lib/checksum.c')
-rw-r--r-- | arch/ia64/lib/checksum.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/arch/ia64/lib/checksum.c b/arch/ia64/lib/checksum.c new file mode 100644 index 000000000000..beb11721d9f5 --- /dev/null +++ b/arch/ia64/lib/checksum.c @@ -0,0 +1,102 @@ +/* + * Network checksum routines + * + * Copyright (C) 1999, 2003 Hewlett-Packard Co + * Stephane Eranian <eranian@hpl.hp.com> + * + * Most of the code coming from arch/alpha/lib/checksum.c + * + * This file contains network checksum routines that are better done + * in an architecture-specific manner due to speed.. + */ + +#include <linux/module.h> +#include <linux/string.h> + +#include <asm/byteorder.h> + +static inline unsigned short +from64to16 (unsigned long x) +{ + /* add up 32-bit words for 33 bits */ + x = (x & 0xffffffff) + (x >> 32); + /* add up 16-bit and 17-bit words for 17+c bits */ + x = (x & 0xffff) + (x >> 16); + /* add up 16-bit and 2-bit for 16+c bit */ + x = (x & 0xffff) + (x >> 16); + /* add up carry.. */ + x = (x & 0xffff) + (x >> 16); + return x; +} + +/* + * computes the checksum of the TCP/UDP pseudo-header + * returns a 16-bit checksum, already complemented. + */ +unsigned short int +csum_tcpudp_magic (unsigned long saddr, unsigned long daddr, unsigned short len, + unsigned short proto, unsigned int sum) +{ + return ~from64to16(saddr + daddr + sum + ((unsigned long) ntohs(len) << 16) + + ((unsigned long) proto << 8)); +} + +EXPORT_SYMBOL(csum_tcpudp_magic); + +unsigned int +csum_tcpudp_nofold (unsigned long saddr, unsigned long daddr, unsigned short len, + unsigned short proto, unsigned int sum) +{ + unsigned long result; + + result = (saddr + daddr + sum + + ((unsigned long) ntohs(len) << 16) + + ((unsigned long) proto << 8)); + + /* Fold down to 32-bits so we don't lose in the typedef-less network stack. */ + /* 64 to 33 */ + result = (result & 0xffffffff) + (result >> 32); + /* 33 to 32 */ + result = (result & 0xffffffff) + (result >> 32); + return result; +} + +extern unsigned long do_csum (const unsigned char *, long); + +/* + * computes the checksum of a memory block at buff, length len, + * and adds in "sum" (32-bit) + * + * returns a 32-bit number suitable for feeding into itself + * or csum_tcpudp_magic + * + * this function must be called with even lengths, except + * for the last fragment, which may be odd + * + * it's best to have buff aligned on a 32-bit boundary + */ +unsigned int +csum_partial (const unsigned char * buff, int len, unsigned int sum) +{ + unsigned long result = do_csum(buff, len); + + /* add in old sum, and carry.. */ + result += sum; + /* 32+c bits -> 32 bits */ + result = (result & 0xffffffff) + (result >> 32); + return result; +} + +EXPORT_SYMBOL(csum_partial); + +/* + * this routine is used for miscellaneous IP-like checksums, mainly + * in icmp.c + */ +unsigned short +ip_compute_csum (unsigned char * buff, int len) +{ + return ~do_csum(buff,len); +} + +EXPORT_SYMBOL(ip_compute_csum); |